# Math Help - Function equations?

1. ## Function equations?

Alright, I have a quiz on this tomorrow and i also can't finish my homework. =/
Any help is appreciated.

Ex 1) Explain how the graph of y = cos(x - $\pi$/3) can be obtained from the graph of y = cos x.

Here, I'm just not sure what they are asking?

Ex 2) A pendulum swings through an angle of 20 degrees each second. If the pendulum is 40 inches long, how far does the tip move each second?

Not sure on this one. I remember something about Linear velocity and/or angular velocity but i could be completely off.

Thanks.

2. Originally Posted by Heiwa
Alright, I have a quiz on this tomorrow and i also can't finish my homework. =/
Any help is appreciated.

Ex 1) Explain how the graph of y = cos(x - $\pi$/3) can be obtained from the graph of y = cos x.

Here, I'm just not sure what they are asking?
it is just asking if you know your transformations. you should know that we obtain the graph of $\cos (x - \pi / 3)$ by shifting the graph of $\cos x$ to the right by $\pi / 3$ units

Ex 2) A pendulum swings through an angle of 20 degrees each second. If the pendulum is 40 inches long, how far does the tip move each second?

Not sure on this one. I remember something about Linear velocity and/or angular velocity but i could be completely off.

Thanks.
nothing so complicated as linear velocity, in fact, it didn't ask us about speed at all. all you want to find here is the length of the arc subtended by an angle of 20 degrees on a circle of radius 40 inches

3. 1) Ok i was thinking that but i wasnt sure it would be so simple.

2) I see, I'm just finding arc length $s$ then. Maybe im just bad at reading math Heh.

Thank you.